Overview
AISI 4140 is one of the most versatile Cr-Mo alloy steels for machined components: high tensile strength (≥ 950 MPa Q&T), good toughness, deep hardenability and excellent response to induction hardening and nitriding. It machines and grinds cleanly in the Q&T condition, holds ±0.01 mm tolerances, and is the industry-standard choice for shafts, gears, hydraulic rods and high-strength fasteners. Shanghai Vertex Alloy Co., Ltd machines 4140 parts from bar, forging or your supplied material, with full heat treatment and inspection in one flow.
Description (English)
Shanghai Vertex Alloy Co., Ltd (Vertex Alloy) supplies AISI 4140 (42CrMo4 / SCM440 / DIN 1.7225) custom machined parts manufactured to your drawing or sample. In-house capabilities: CNC turning Ø 5–400 mm, 3/4/5-axis milling, grinding to ±0.005 mm, deep-hole drilling Ø 4–60 mm; heat treatments: Q&T 28–34 HRC, induction hardening 52–56 HRC, nitriding HV 900+; surface treatments: black oxide, zinc plating, phosphate, hard chrome. Tolerance ±0.01 mm, MOQ 1 piece, EN 10204 3.1 certificates with 100% dimension and hardness inspection. Reverse engineering from worn parts without drawing is available. Widely used for machinery shafts and gears, oil & gas valve parts, automotive axles, hydraulic piston rods, mold components and high-strength fasteners.
Size Range
- CNC Turning Diameter:Ø 5–400 mm
- Turning Max Length:1,000 mm
- Milling Envelope:1,200 × 600 × 600 mm
- Grinding Tolerance:±0.005 mm
- Drilling / Tapping:M2–M48
- Deep Hole Drilling: Ø 4–60 mm
- Part Weight:0.01–500 kg
Grade Specification
| System | Value |
|---|---|
| USA (ASTM/SAE) | AISI 4140 / UNS G41400 |
| Germany / EU (EN) | 42CrMo4 / DIN 1.7225 |
| Japan (JIS) | SCM440 |
| China (GB) | 42CrMo |
| ISO | 42CrMo4 |
Chemical Composition
| Element | Value |
|---|---|
| C | 0.38–0.43 |
| Si | 0.15–0.35 |
| Mn | 0.75–1.00 |
| Cr | 0.80–1.10 |
| Mo | 0.15–0.25 |
| P | ≤ 0.035 |
| S | ≤ 0.040 |
| Fe | Balance |
Mechanical Properties
| productCenter.property | Value |
|---|---|
| Tensile Strength | ≥ 950 MPa |
| Yield Strength | ≥ 750 MPa |
| Elongation | ≥ 12% |
| Reduction of Area | ≥ 45% |
| Hardness (Q&T) | 28–34 HRC |
| Max Hardness (Quenched) | up to 54 HRC |
| Impact Energy (KV, 20°C) | ≥ 47 J |
Physical Properties
| Property | Unit | Value |
|---|---|---|
| Density | g/cm³ | 7.85 g/cm³ |
| Elastic Modulus | GPa | 205 GPa |
| Thermal Conductivity | W/m·K | 42.6 W/(m·K) at 100°C |
| Specific Heat | J/kg·K | 473 J/(kg·K) |
| Electrical Resistivity | μΩ·cm | 0.22 µΩ·m |
| CTE (20–100°C) | - | 12.2 × 10⁻⁶ /K |
| Poisson's Ratio | - | 0.29 |
Applications
- Machinery:Shafts
- Machinery:Spindles
- Machinery Gears & pinions
- Oil & Gas Valve parts
- Oil & Gas Drill tool components
- Oil & Gas Pump shafts
- Automotive Axles
- Automotive Steering knuckles
- Hydraulics Cylinder rods & piston rods
- Hydraulics Fittings
- Molds & Tooling Die holders & wear inserts
- Fasteners High-strength bolts 10.9 / 12.9
- Mining / Construction Rollers & undercarriage pins
- Plastics Machinery Screws, barrels, tie bars